Our aim is to examine usefulness of CUE readings for predicting and confirming ovulation. Methodological refinements will be used to develop it into an instrument that will be simple, inexpensive, and reliable. A detailed and expanded investigation of the concept will be done at the primary site (data on greater than 300 cycles) with independent verification on a smaller scale (150 cycles) at secondary sites. Besides luteinizing hormone assays for defining ovulation in most cycles ultrasound will be used un 70 cycles to examine the relation of CUE reading changes to ovulation. Since a thorough understanding of the physiological mechanisms involved is important, the relationships between ACTH, aldosterone, salivary electrolytes, and CUE salivary readings (SR) will be examined. As part of this trial, the contributions of estrogen through the renin-angiotensin system to changes in aldosterone, hence SR, will be defined. Usefulness of the method in induced ovulations was indicated in preliminary studies. This will be an important market segment, therefore, this application will be studied in 40 clomiphene and 20 "pergonal" induced cycles. Methodological development will be directed toward refining of sensor design, evaluating sodium-specific sensors, miniaturizing and prototyping the final microprocessor based instrument.